The removal of SO.sub.x (that is oxides of sulfur) from industrial waste gases such as combustion gases, both from power generating units, gas and oil heating units, internal combustion engines and regenerator gases from petroleum cracking plants and other sources which affect the quality of the air, is an ongoing problem.
It has been suggested that SO.sub.2 in combustion gases may be oxidized by solutions of ferric sulfate (see U.S. Pat. No. 4,070,441, and references cited in said patent).
The Iida, et al U.S. Pat. No. 3,459,495, discloses the use of quinone compounds to convert H.sub.2 S to sulfur. See also Hasebe "The Takahax Wet Desulfurization Process": CEER, pages 27 et seq, March, 1970. The Canadian Pat. No. 672,084 discloses the use for such purpose of anthroquinone disulfonic acid mixed with a metal chelated by tartaric acid or EDTA (ethylene diamine tetra acetic acid).
My U.S. Pat. No. 3,937,795, discloses the conversion of H.sub.2 S to sulfur by employing quinone compounds which have been complexed with a metal. These complexes are referred to as chelates.
It has been known that the sulfite ion will adduct nitric oxide (NO). Nunes et al. "Kinetics of the Reaction of Nitric Oxide and Sulfite," Inorganic Chemistry, Vol. 9, No. 8, 1970, pp. 1916 and 1917.